Dynamics Of A Nonautonomous Three-species Predator-prey System With The Beddington-DeAngelis Functional Reponese

In this paper,we systematically study a non-autonomous three-species predatorprey system with the Beddington-DeAngelis functional reponese.We address such properties as positive invariance,permanence,non-persistence for the system.For the periodic case,the condition for existence of a positive periodic solution is obtianed.